Yesterday, during the opening hours of the D6 conference, Walt Mossberg and Kara Swisher jointly interviewed Steve Ballmer and Bill Gates. While the interview dealt mostly with the past, Yahoo, and a bit of Vista, by far the most interesting part was the first ever public appearance of Vista's successor: Windows 7. Earlier today, the team behind D6 posted a video of the demonstration, which was conducted by Microsoft's Julie Larson-Green. From a graphical user interface point of view, there were some interesting things in there.

Current systems, as I understand them capture what's being displayed and apply varying degrees of compression to it before sending the output across the network. Theoretically, with a 3D accelerated desktop you could just send the instructions for drawing the primitives the desktop is composed of across the network and have the GPU at the other side render them freeing up processing power on the server side and allowing for higher quality and a richer experience on the client side.

Not every remote desktop implementation works by capturing a bitmap and sending it across the network. VNC works like this, but RDP or ICA or even X work differently.
They do exactly what you just described: they send graphics command across the network and the client interprets them, by rendering what the server sent.